from math import sqrt


num = int(input('请输入一个数值:'))
end = int(sqrt(num))
is_Prime = True

for x in range(2,end+1):
    if num % x == 0:
        is_Prime = False
        break

if is_Prime and num != 1:
    print(f'{num}是素数')
else:
    print(f'{num}不是素数')